void
udld_print (const u_char *pptr, u_int length)
{
int code, type, len;
const u_char *tptr;
if (length < UDLD_HEADER_LEN)
goto trunc;
tptr = pptr;
if (!TTEST2(*tptr, UDLD_HEADER_LEN))
goto trunc;
code = UDLD_EXTRACT_OPCODE(*tptr);
printf("UDLDv%u, Code %s (%x), Flags [%s] (0x%02x), length %u",
UDLD_EXTRACT_VERSION(*tptr),
tok2str(udld_code_values, "Reserved", code),
code,
bittok2str(udld_flags_values, "none", *(tptr+1)),
*(tptr+1),
length);
/*
* In non-verbose mode, just print version and opcode type
*/
if (vflag < 1) {
return;
}
printf("\n\tChecksum 0x%04x (unverified)", EXTRACT_16BITS(tptr+2));
tptr += UDLD_HEADER_LEN;
while (tptr < (pptr+length)) {
if (!TTEST2(*tptr, 4))
goto trunc;
type = EXTRACT_16BITS(tptr);
len = EXTRACT_16BITS(tptr+2);
len -= 4;
tptr += 4;
/* infinite loop check */
if (type == 0 || len == 0) {
return;
}
printf("\n\t%s (0x%04x) TLV, length %u",
tok2str(udld_tlv_values, "Unknown", type),
type, len);
switch (type) {
case UDLD_DEVICE_ID_TLV:
case UDLD_PORT_ID_TLV:
case UDLD_ECHO_TLV:
case UDLD_DEVICE_NAME_TLV:
printf(", %s", tptr);
break;
case UDLD_MESSAGE_INTERVAL_TLV:
case UDLD_TIMEOUT_INTERVAL_TLV:
printf(", %us", (*tptr));
break;
case UDLD_SEQ_NUMBER_TLV:
printf(", %u", EXTRACT_32BITS(tptr));
break;
default:
break;
}
tptr += len;
}
return;
trunc:
printf("[|udld]");
}
void
udld_print(netdissect_options *ndo, const u_char *pptr, u_int length)
{
int code, type, len;
const u_char *tptr;
ndo->ndo_protocol = "udld";
if (length < UDLD_HEADER_LEN)
goto trunc;
tptr = pptr;
ND_TCHECK_LEN(tptr, UDLD_HEADER_LEN);
code = UDLD_EXTRACT_OPCODE(EXTRACT_U_1(tptr));
ND_PRINT("UDLDv%u, Code %s (%x), Flags [%s] (0x%02x), length %u",
UDLD_EXTRACT_VERSION(EXTRACT_U_1(tptr)),
tok2str(udld_code_values, "Reserved", code),
code,
bittok2str(udld_flags_values, "none", EXTRACT_U_1((tptr + 1))),
EXTRACT_U_1((tptr + 1)),
length);
/*
* In non-verbose mode, just print version and opcode type
*/
if (ndo->ndo_vflag < 1) {
return;
}
ND_PRINT("\n\tChecksum 0x%04x (unverified)", EXTRACT_BE_U_2(tptr + 2));
tptr += UDLD_HEADER_LEN;
while (tptr < (pptr+length)) {
ND_TCHECK_4(tptr);
type = EXTRACT_BE_U_2(tptr);
len = EXTRACT_BE_U_2(tptr + 2);
ND_PRINT("\n\t%s (0x%04x) TLV, length %u",
tok2str(udld_tlv_values, "Unknown", type),
type, len);
if (type == 0)
goto invalid;
/* infinite loop check */
if (len <= 4)
goto invalid;
len -= 4;
tptr += 4;
ND_TCHECK_LEN(tptr, len);
switch (type) {
case UDLD_DEVICE_ID_TLV:
case UDLD_PORT_ID_TLV:
case UDLD_DEVICE_NAME_TLV:
ND_PRINT(", ");
nd_printzp(ndo, tptr, len, NULL);
break;
case UDLD_ECHO_TLV:
ND_PRINT(", ");
(void)nd_printn(ndo, tptr, len, NULL);
break;
case UDLD_MESSAGE_INTERVAL_TLV:
case UDLD_TIMEOUT_INTERVAL_TLV:
if (len != 1)
goto invalid;
ND_PRINT(", %us", (EXTRACT_U_1(tptr)));
break;
case UDLD_SEQ_NUMBER_TLV:
if (len != 4)
goto invalid;
ND_PRINT(", %u", EXTRACT_BE_U_4(tptr));
break;
default:
break;
}
tptr += len;
}
return;
invalid:
ND_PRINT("%s", istr);
return;
trunc:
nd_print_trunc(ndo);
}
